1Z0-068 · Question #22
Which two statements are true concerning buffer states as shown in GV$BH.STATUS in Oracle 12c RAC?
The correct answer is A. An XCUR block image may exist for a specific database block in only one instance. B. A CR image may get served from one instance to another to satisfy a read request. A: xcur is a RAM block that has been acquired in exclusive current mode. According the Oracle documentation, if a buffer state is exclusive current (XCUR), an instance owns the resource in B: cr mode indicates a "cloned" RAM block (a "stale" block), that was once in xcur mode…
Question
Which two statements are true concerning buffer states as shown in GV$BH.STATUS in Oracle 12c RAC?
Options
- AAn XCUR block image may exist for a specific database block in only one instance.
- BA CR image may get served from one instance to another to satisfy a read request.
- CAn XCUR image is not downgraded to a SCUR image for shipping to another instance until
- DA PI block image may exist for a specific database block in only one instance.
How the community answered
(51 responses)- A73% (37)
- C8% (4)
- D20% (10)
Explanation
A: xcur is a RAM block that has been acquired in exclusive current mode. According the Oracle documentation, if a buffer state is exclusive current (XCUR), an instance owns the resource in B: cr mode indicates a "cloned" RAM block (a "stale" block), that was once in xcur mode. The instance has shared access to the block and can only perform reads. The cr state means the owning instance can perform a consistent read of the block, if the instance holds an older version
Topics
Community Discussion
No community discussion yet for this question.